SC 13D

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

______________________

SCHEDULE 13D

Under the Securities Exchange Act of 1934
(Amendment No. )*

______________________

HYLIION HOLDINGS CORP.

(Name of Issuer)

Common Stock, par value $0.0001 per share

(Title of Class of Securities)

449109 107

(CUSIP Number)

Howard M. Jenkins

c/o Axioma Management, LLC

601 South Boulevard

Tampa, Florida 33606

(813) 760-2229

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

October 1, 2020

(Date of Event Which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §240.13d-1(e), §240.13d-1(f) or §240.13d-1(g), check the following box. ☐

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See §240.13d-7 for other parties to whom copies are to be sent.

* The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

CUSIP No. 449109 107

1.	Names of reporting persons. Axioma Ventures, LLC
2.	Check the appropriate box if a member of a group (see instructions)		(a) ☐ (b) ☒
3.	SEC use only
4.	Source of funds (see instructions) WC
5.	Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)		☐
6.	Citizenship or place of organization Florida
Number of Shares Beneficially owned by each Reporting person with	7.	Sole voting power 0
	8.	Shared voting power 16,656,790 (1)
	9.	Sole dispositive power 0
	10.	Shared dispositive power 16,656,790 (1)
11.	Aggregate amount beneficially owned by each reporting person 16,656,790 (1)
12.	Check if the aggregate amount in Row (11) excludes certain shares (see instructions)		☐
13.	Percent of class represented by amount in Row (11) 10.82% (1)
14.	Type of reporting person (see instructions) OO

(1) Based on 153,901,829 shares of common stock, par value $0.0001 per share (the “Common Stock”), outstanding as of October 1, 2020.

Page 2 of 11 

CUSIP No. 449109 107

1.	Names of reporting persons. Axioma Holdings, LLC
2.	Check the appropriate box if a member of a group (see instructions)		(a) ☐ (b) ☒
3.	SEC use only
4.	Source of funds (see instructions) AF
5.	Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)		☐
6.	Citizenship or place of organization Florida
Number of Shares Beneficially owned by each Reporting person with	7.	Sole voting power 0
	8.	Shared voting power 16,656,790 (1)
	9.	Sole dispositive power 0
	10.	Shared dispositive power 16,656,790 (1)
11.	Aggregate amount beneficially owned by each reporting person 16,656,790 (1)
12.	Check if the aggregate amount in Row (11) excludes certain shares (see instructions)		☐
13.	Percent of class represented by amount in Row (11) 10.82% (1)
14.	Type of reporting person (see instructions) HC

(1) Based on 153,901,829 shares of Common Stock outstanding as of October 1, 2020.

Page 3 of 11 

CUSIP No. 449109 107

1.	Names of reporting persons. Axioma Management, LLC
2.	Check the appropriate box if a member of a group (see instructions)		(a) ☐ (b) ☒
3.	SEC use only
4.	Source of funds (see instructions) AF
5.	Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)		☐
6.	Citizenship or place of organization Florida
Number of Shares Beneficially owned by each Reporting person with	7.	Sole voting power 0
	8.	Shared voting power 16,656,790 (1)
	9.	Sole dispositive power 0
	10.	Shared dispositive power 16,656,790 (1)
11.	Aggregate amount beneficially owned by each reporting person 16,656,790 (1)
12.	Check if the aggregate amount in Row (11) excludes certain shares (see instructions)		☐
13.	Percent of class represented by amount in Row (11) 10.82%
14.	Type of reporting person (see instructions) HC

(1) Based on 153,901,829 shares of Common Stock outstanding as of October 1, 2020.

Page 4 of 11 

CUSIP No. 449109 107

1.	Names of reporting persons. Howard M. Jenkins
2.	Check the appropriate box if a member of a group (see instructions)		(a) ☐ (b) ☒
3.	SEC use only
4.	Source of funds (see instructions) AF
5.	Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)		☐
6.	Citizenship or place of organization United States
Number of Shares Beneficially owned by each Reporting person with	7.	Sole voting power 0
	8.	Shared voting power 16,656,790 (1)
	9.	Sole dispositive power 0
	10.	Shared dispositive power 16,656,790 (1)
11.	Aggregate amount beneficially owned by each reporting person 16,656,790 (1)
12.	Check if the aggregate amount in Row (11) excludes certain shares (see instructions)		☐
13.	Percent of class represented by amount in Row (11) 10.82% (1)
14.	Type of reporting person (see instructions) IN

(1) Based on 153,901,829 shares of Common Stock outstanding as of October 1, 2020.

Page 5 of 11 

CUSIP No. 449109 107

1.	Names of reporting persons. Alexander H. Jenkins
2.	Check the appropriate box if a member of a group (see instructions)		(a) ☐ (b) ☒
3.	SEC use only
4.	Source of funds (see instructions) AF
5.	Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)		☐
6.	Citizenship or place of organization United States
Number of Shares Beneficially owned by each Reporting person with	7.	Sole voting power 0
	8.	Shared voting power 16,656,790 (1)
	9.	Sole dispositive power 0
	10.	Shared dispositive power 16,656,790 (1)
11.	Aggregate amount beneficially owned by each reporting person 16,656,790 (1)
12.	Check if the aggregate amount in Row (11) excludes certain shares (see instructions)		☐
13.	Percent of class represented by amount in Row (11) 10.82% (1)
14.	Type of reporting person (see instructions) IN

(1) Based on 153,901,829 shares of Common Stock outstanding as of October 1, 2020.

Page 6 of 11 

CUSIP No. 449109 107

1.	Names of reporting persons. Kiran Lingam
2.	Check the appropriate box if a member of a group (see instructions)		(a) ☐ (b) ☒
3.	SEC use only
4.	Source of funds (see instructions) AF
5.	Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)		☐
6.	Citizenship or place of organization United States
Number of Shares Beneficially owned by each Reporting person with	7.	Sole voting power 0
	8.	Shared voting power 16,656,790 (1)
	9.	Sole dispositive power 0
	10.	Shared dispositive power 16,656,790 (1)
11.	Aggregate amount beneficially owned by each reporting person 16,656,790 (1)
12.	Check if the aggregate amount in Row (11) excludes certain shares (see instructions)		☐
13.	Percent of class represented by amount in Row (11) 10.82% (1)
14.	Type of reporting person (see instructions) IN

(1) Based on 153,901,829 shares of Common Stock outstanding as of October 1, 2020.

Page 7 of 11 

CUSIP No. 449109 107

Item 1. Security and Issuer.

This Schedule 13D (this “Schedule 13D”) relates to the common stock, par value $0.0001 per share (the “Common Stock”), of Hyliion Holdings Corp., a Delaware corporation (formerly Tortoise Acquisition Corp.) (the “Issuer”). The principal executive offices of the Issuer are located at 1202 BMC Drive, Suite 100, Cedar Park, TX 78613.

Item 2. Identity and Background.

The persons filing this statement and the persons enumerated in Instruction C of Schedule 13D and, where applicable, their respective places of organization, general partners, directors, executive officers and controlling persons and the information regarding them, are as follows:

(a)       This Schedule 13D is filed by:

·Axioma Ventures, LLC, a Florida limited liability company (“Axioma Ventures”);

·Axioma Holdings, LLC, a Florida limited liability company (“Axioma Holdings”);

·Axioma Management, LLC, a Florida limited liability company (“Axioma Management”);

·Howard M. Jenkins, a director of the Issuer;

·Alexander H. Jenkins; and

·Kiran Lingam.

The foregoing persons are hereinafter sometimes collectively referred to as the “Reporting Persons.” The shares of Common Stock to which this Schedule 13D relates are held of record by Axioma Ventures. The sole member of Axioma Ventures is Axioma Holdings and the managers of Axioma Ventures are Alexander Jenkins and Kiran Lingam.   The sole manager of Axioma Holdings is Axioma Management.  Howard Jenkins, Alexander Jenkins and Kiran Lingam are managers of Axioma Management.  Each of Axioma Holdings, Axioma Management, Howard Jenkins, Alexander Jenkins and Kiran Lingam therefore may be deemed to share voting and dispositive power with respect to the shares of Common Stock held of record by Axioma Ventures.  In addition, Howard M. Jenkins serves as Class II director of the Issuer, with his term expiring at the Issuer’s 2022 annual meeting of stockholders.

(b) The business address of the Reporting Persons is c/o Axioma Management, LLC, 601 South Boulevard, Tampa, FL 33606.

(c) The present principal occupation or employment of each of the Reporting Persons and the name, principal business and address of any corporation or other organization in which such employment is conducted is as follows:

· Axioma Ventures is a venture capital firm with its address at 601 South Boulevard, Tampa, FL 33606.

· Axioma Holdings and Axioma Management are holding companies engaged, through their subsidiaries, in investments.

· Howard Jenkins, Alexander Jenkins and Kiran Lingam are each managers at Axioma Management, which is engaged, through its subsidiaries, in investments, and has its principal business address at 601 South Boulevard, Tampa, FL 33606.

(d) During the last five years, none of the Reporting Persons has been convicted in a criminal proceeding (excluding traffic violations or similar misdemeanors).

(e) During the last five years, none of the Reporting Persons was a party to a civil proceeding of a judicial or administrative body of competent jurisdiction and as a result of such proceeding was or is subject to a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws or finding any violation with respect to such laws.

(f) The citizenship or place of organization for each of the Reporting Persons is listed in Row 6 of the cover pages hereto.

Page 8 of 11 

CUSIP No. 449109 107

Item 3. Source and Amount of Funds or Other Consideration.

The consideration used to acquire beneficial ownership of the shares of Common Stock of the Issuer consisted of securities of Hyliion Inc. (“Legacy Hyliion”). The Reporting Persons acquired the shares of Common Stock pursuant to the Business Combination Agreement and Plan of Reorganization, dated as of June 18, 2020 (the “Business Combination Agreement”), by and among Tortoise Acquisition Corp. (“Tortoise”), Legacy Hyliion and SHLL Merger Sub Inc., a wholly-owned subsidiary of Tortoise (“Merger Sub”), pursuant to which Merger Sub merged (the “Merger”) with and into Legacy Hyliion, with Legacy Hyliion surviving the merger as a wholly-owned subsidiary of Tortoise (which subsequently changed its name to “Hyliion Holdings Corp.”). Axioma Ventures used working capital in order to acquire the securities of Legacy Hyliion.

Item 4. Purpose of Transaction.

The information provided in response to Items 2 and 3 hereof is incorporated herein by reference.

The Reporting Persons acquired the Common Stock for investment purposes in the Reporting Persons’ ordinary course of business. In pursuing such investment purposes, the Reporting Persons may further purchase, hold, vote, trade, dispose or otherwise deal in the Common Stock at times, and in such manner (including pursuant to hedging transactions), as they deem advisable to benefit from changes in market prices of the Common Stock, changes in the Issuer’s operations, business strategy or prospects, or from a sale or merger of the Issuer. To evaluate such alternatives, the Reporting Persons routinely will monitor the Issuer’s operations, prospects, business development, management, competitive and strategic matters, capital structure, and prevailing market conditions, as well as alternative investment opportunities, liquidity requirements of the Reporting Persons and other investment considerations. Consistent with their investment research methods and evaluation criteria, the Reporting Persons may discuss such matters with management or directors of the Issuer, other shareholders, industry analysts, existing or potential strategic partners or competitors, investment and financing professionals, sources of credit and other investors. Such factors and discussions may materially affect, and result in, the Reporting Persons’ modifying their ownership of the Common Stock, exchanging information with the Issuer pursuant to appropriate confidentiality or similar agreements, proposing changes in the Issuer’s operations, governance or capitalization, or in proposing one or more of the other actions described in paragraphs (a) through (j) of Item 4 of Schedule 13D. The Reporting Persons reserve the right to formulate other plans and/or make other proposals, and take such actions with respect to their investment in the Issuer, including any or all of the actions set forth in paragraphs (a) through (j) of Item 4 of Schedule 13D, or acquire additional shares of Common Stock or dispose of all shares of Common Stock beneficially owned by them, in the public market or privately negotiated transactions. The Reporting Persons may at any time reconsider and change their plans or proposals relating to the foregoing.

Item 5. Interest in Securities of the Issuer.

(a) – (b)

The information relating to the beneficial ownership of Common Stock by each of the Reporting Persons set forth in Rows 7 through 13 of the cover pages hereto is incorporated by reference herein. The percentages set forth in Row 13 for all cover pages filed herewith are calculated based upon 153,901,829 shares of Common Stock outstanding, as set forth in the Issuer’s Current Report on Form 8-K filed with the Securities and Exchange Commission on October 7, 2020.

(c)

Except as set forth in Item 4 hereof, the Reporting Persons have not effected any transactions in the Common Stock in the sixty (60) days preceding the date of this Schedule 13D.

(d) Except as set forth in Item 6 hereof, no person has the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the Common Stock reported herein.

(e) Not applicable.

The information in Items 4 and 6 hereof is incorporated by reference herein.

Page 9 of 11 

CUSIP No. 449109 107

Item 6. Contracts, Arrangements, Understandings or Relationships With Respect to Securities of the Issuer.

The information in Items 2 and 3 is incorporated by reference herein.

In connection with the Merger, on October 1, 2020, the Issuer and certain stockholders of Legacy Hyliion, including Axioma Ventures, and executives of the Company (the “Legacy Holders”) entered into a Lock-Up Agreement (each, a “Lock-Up Agreement”). The terms of the Lock-Up Agreements provide for the Common Stock held by the Legacy Holders as of immediately after the Merger to be locked-up for a period of 180 days after the closing of the Merger, subject to certain exceptions.

In connection with the Merger, the Issuer entered into an Amended and Restated Registration Rights Agreement with several parties (the “Holders”), including Axioma Ventures, pursuant to which the Holders, subject to certain conditions, are entitled to registration rights with respect to securities of the Issuer (the “Registrable Securities”). Pursuant to this agreement, the Issuer agreed that, within 30 calendar days after the consummation of the Merger, it will file with the SEC a registration statement registering the resale of the Registrable Securities, and use its reasonable best efforts to have such registration statement declared effective by the SEC as soon as reasonably practicable after the filing thereof. Certain of the Holders were granted demand underwritten offering registration rights and all of the Holders were granted piggyback registration rights. The agreement terminates upon the earlier of (a) ten years following the Merger or (b) the date as of which the Holders cease to hold any registrable securities.

The Reporting Persons are parties to an agreement with respect to the joint filing of this Schedule 13D and any amendments hereto. A copy of such agreement is attached as Exhibit 1 to this Schedule 13D and is incorporated by reference herein.

Item 7. Material to Be Filed as Exhibits.

Exhibit    No.	Description
1*	Joint Filing Agreement, dated October 13, 2020.
2*	Form of Lock-Up Agreement, dated October 1, 2020.

3* Amended and Restated Registration Rights Agreement, dated October 1, 2020.

* Filed herewith.

Page 10 of 11 

CUSIP No. 449109 107

SIGNATURES

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

DATED: October 13, 2020

AXIOMA VENTURES, LLC

By:  AXIOMA HOLDINGS, LLC, its sole member

By: AXIOMA MANAGEMENT, LLC, its manager

By: /s/ Howard M. Jenkins

       Howard M. Jenkins, manager

AXIOMA HOLDINGS, LLC

By: AXIOMA MANAGEMENT, LLC, its manager

By: /s/ Howard M. Jenkins

       Howard M. Jenkins, manager

AXIOMA MANAGEMENT, LLC

By: /s/ Howard M. Jenkins

       Howard M. Jenkins, manager

/s/ Howard M. Jenkins

Howard M. Jenkins

/s/ Alexander H. Jenkins

Alexander H. Jenkins

/s/ Kiran Lingam

Kiran Lingam

Page 11 of 11

EX-1

EXHIBIT 1

JOINT FILING AGREEMENT

In accordance with Rule 13d-1(k) of the Securities Exchange Act of 1934, as amended, the undersigned agree to the joint filing on behalf of each of them of a Statement on Schedule 13D (including any and all amendments thereto) with respect to the shares of common stock, par value $0.0001 per share, of Hyliion Holdings Corp. and further agree that this Joint Filing Agreement shall be included as an Exhibit to such joint filing.

This Joint Filing Agreement may be executed in separate counterparts, each of which shall be deemed an original, but all of which shall constitute one and the same instrument.

IN WITNESS WHEREOF, the parties have executed this Joint Filing Agreement on October 13, 2020.

AXIOMA VENTURES, LLC

By:  AXIOMA HOLDINGS, LLC, its sole member

By: AXIOMA MANAGEMENT, LLC, its manager

By: /s/ Howard M. Jenkins

       Howard M. Jenkins, manager

AXIOMA HOLDINGS, LLC

By: AXIOMA MANAGEMENT, LLC, its manager

By: /s/ Howard M. Jenkins

       Howard M. Jenkins, manager

AXIOMA MANAGEMENT, LLC

By: /s/ Howard M. Jenkins

       Howard M. Jenkins, manager

/s/ Howard M. Jenkins

Howard M. Jenkins

/s/ Alexander H. Jenkins

Alexander H. Jenkins

/s/ Kiran Lingam

Kiran Lingam

EX-2

October 1, 2020

Hyliion Holdings Corp.

1202 BMC Drive

Cedar Park, TX 78613

Re: Lock-Up Agreement

Ladies and Gentlemen:

This letter (this “Letter Agreement”) is being delivered to you in accordance with the Business Combination Agreement and Plan of Reorganization (the “BCA”) entered into by and among Hyliion Holdings Corp., a Delaware corporation f/k/a Tortoise Acquisition Corp. (the “Company”), SHLL Merger Sub Inc., a Delaware corporation and wholly owned subsidiary of the Company (“Merger Sub”), and Hyliion Inc., a Delaware corporation (“Hyliion”), pursuant to which, among other things, Merger Sub will be merged with and into Hyliion on or about the date hereof (the “Merger”), with Hyliion surviving the Merger as a wholly owned subsidiary of the Company.

In order to induce the Company to proceed with the Merger and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the undersigned (the “Securityholder”) hereby agrees with the Company as follows:

1. Subject to the exceptions set forth herein, the Securityholder agrees not to, without the prior written consent of the board of directors of the Company, (i) sell, offer to sell, contract or agree to sell, hypothecate, pledge, grant any option to purchase or otherwise dispose of or agree to dispose of, directly or indirectly, or establish or increase a put equivalent position or liquidate or decrease a call equivalent position within the meaning of Section 16 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and the rules and regulations of the Securities and Exchange Commission promulgated thereunder, any shares of Class A Common Stock, par value $0.0001 per share, of the Company (“Class A Common Stock”) held by it immediately after the effective time of the Merger, any shares of Class A Common Stock issuable upon the exercise of options to purchase shares of Class A Common Stock held by it immediately after the effective time of the Merger, or any securities convertible into or exercisable or exchangeable for Class A Common Stock held by it immediately after the effective time of the Merger, (ii) enter into any swap or other arrangement that transfers to another, in whole or in part, any of the economic consequences of ownership of any of such shares of Class A Common Stock or securities convertible into or exercisable or exchangeable for Class A Common Stock, whether any such transaction is to be settled by delivery of such securities, in cash or otherwise or (iii) publicly announce any intention to effect any transaction specified in clause (i) or (ii) (the actions specified in clauses (i)-(iii), collectively, “Transfer”) until 180 days after the closing date of the Merger (the “Lock-up”).

2. The restrictions set forth in paragraph 1 shall not apply to:

(i) in the case of an entity, Transfers to a stockholder, partner, member or affiliate of such entity;

(ii) in the case of an individual, Transfers by gift to members of the individual’s immediate family (as defined below) or to a trust, the beneficiary of which is a member of one of the individual’s immediate family, an affiliate of such person or to a charitable organization;

(iii) in the case of an individual, Transfers by virtue of laws of descent and distribution upon death of the individual;

(iv) in the case of an individual, Transfers pursuant to a qualified domestic relations order;

(v) in the case of an entity, Transfers by virtue of the laws of the state of the entity’s organization and the entity’s organizational documents upon dissolution of the entity;

(vi) transactions relating to Class A Common Stock or other securities convertible into or exercisable or exchangeable for Class A Common Stock acquired in open market transactions after the effective time of the Merger, provided that no such transaction is required to be, or is, publicly announced (whether on Form 4, Form 5 or otherwise, other than a required filing on Schedule 13F, 13G or 13G/A) during the Lock-Up;

(vii) the exercise of any options or warrants to purchase Class A Common Stock (which exercises may be effected on a cashless basis to the extent the instruments representing such options or warrants permit exercises on a cashless basis);

(viii) Transfers to the Company to satisfy tax withholding obligations pursuant to the Company’s equity incentive plans or arrangements;

(ix) Transfers to the Company pursuant to any contractual arrangement in effect at the effective time of the Merger that provides for the repurchase by the Company or forfeiture of the Securityholder’s Class A Common Stock or other securities convertible into or exercisable or exchangeable for Class A Common Stock in connection with the termination of the Securityholder’s service to the Company;

(x) the entry, by the Securityholder, at any time after the effective time of the Merger, of any trading plan providing for the sale of Class A Common Stock by the Securityholder, which trading plan meets the requirements of Rule 10b5-1(c) under the Exchange Act, provided, however, that such plan does not provide for, or permit, the sale of any Class A Common Stock during the Lock-Up and no public announcement or filing is voluntarily made or required regarding such plan during the Lock-Up;

(xi) transactions in the event of completion of a liquidation, merger, stock exchange or other similar transaction which results in all of the Company’s securityholders having the right to exchange their shares of Class A Common Stock for cash, securities or other property; and

(xii) transactions to satisfy any U.S. federal, state, or local income tax obligations of the Securityholder (or its direct or indirect owners) arising from a change in the U.S. Internal Revenue Code of 1986, as amended (the “Code”), or the U.S. Treasury Regulations promulgated thereunder (the “Regulations”) after the date on which the BCA was executed by the parties, and such change prevents the Merger from qualifying as a “reorganization” pursuant to Section 368 of the Code (and the Merger does not qualify for similar tax-free treatment pursuant to any successor or other provision of the Code or Regulations taking into account such changes).

provided, however, that (A) in the case of clauses (i) through (v), these permitted transferees must enter into a written agreement, in substantially the form of this Letter Agreement (it being understood that any references to “immediate family” in the agreement executed by such transferee shall expressly refer only to the immediate family of the Securityholder and not to the immediate family of the transferee), agreeing to be bound by these Transfer restrictions. For purposes of this paragraph, “immediate family” shall mean a spouse, domestic partner, child, grandchild or other lineal descendant (including by adoption), father, mother, brother or sister of the undersigned; and “affiliate” shall have the meaning set forth in Rule 405 under the Securities Act of 1933, as amended.

3. This Letter Agreement constitutes the entire agreement and understanding of the parties hereto in respect of the subject matter hereof and supersedes all prior understandings, agreements or representations by or among the parties hereto, written or oral, to the extent they relate in any way to the subject matter hereof or the transactions contemplated hereby. This Letter Agreement may not be changed, amended, modified or waived (other than to correct a typographical error) as to any particular provision, except by a written instrument executed by all parties hereto.

4. No party hereto may assign either this Letter Agreement or any of its rights, interests or obligations hereunder without the prior written consent of the other party. Any purported assignment in violation of this paragraph shall be void and ineffectual and shall not operate to transfer or assign any interest or title to the purported assignee. This Letter Agreement shall be binding on the Securityholder and each of its respective successors, heirs and assigns and permitted transferees.

5. This Letter Agreement shall be governed by and construed and enforced in accordance with the laws of the State of Delaware, without giving effect to conflicts of law principles that would result in the application of the substantive laws of another jurisdiction. The parties hereto (i) all agree that any action, proceeding, claim or dispute arising out of, or relating in any way to, this Letter Agreement shall be brought and enforced in any Delaware Chancery Court, and irrevocably submit to such jurisdiction and venue, which jurisdiction and venue shall be exclusive and (ii) waive any objection to such exclusive jurisdiction and venue or that such courts represent an inconvenient forum.

6. This Letter Agreement shall terminate on the expiration of the Lock-up.

[remainder of page intentionally left blank]

Very truly yours,

(Signature)

(Name of Signatory if Securityholder is an entity – Please Print)

(Title of Signatory if Securityholder is an entity – Please Print)

Address:  

[Signature Page to Lock-Up Agreement]

EX-3

AMENDED AND RESTATED REGISTRATION RIGHTS AGREEMENT

THIS AMENDED AND RESTATED REGISTRATION RIGHTS AGREEMENT (this “Agreement”), dated as of October 1, 2020, is made and entered into by and among Hyliion Holdings Corp., a Delaware corporation f/k/a Tortoise Acquisition Corp. (the “Company”), Tortoise Sponsor LLC, a Delaware limited liability company (the “Sponsor”), TortoiseEcofin Borrower LLC, a Delaware limited liability company (“Tortoise Borrower”), and the undersigned parties listed under Holder on the signature pages hereto (each such party, together with the Sponsor, Tortoise Borrower and any person or entity who hereafter becomes a party to this Agreement pursuant to Section 5.2 of this Agreement, a “Holder” and collectively the “Holders”).

RECITALS

WHEREAS, on February 27, 2019, the Company, the Sponsor, Atlas Point Energy Infrastructure Fund, LLC, a Delaware limited liability company (“Atlas Point”), Tortoise Borrower and certain other security holders named therein entered into that certain Registration Rights Agreement (the “Existing Registration Rights Agreement”), pursuant to which the Company granted the Sponsor, Atlas Point, Tortoise Borrower and such other holders named therein certain registration rights with respect to certain securities of the Company;

WHEREAS, on June 18, 2020, the Company, SHLL Merger Sub Inc., a Delaware corporation and wholly owned subsidiary of the Company (“Merger Sub”), and Hyliion Inc., a Delaware corporation (“Hyliion”), entered into that certain Business Combination Agreement and Plan of Reorganization, pursuant to which Merger Sub will merge with and into Hyliion on or about the date hereof, with Hyliion surviving the merger as a wholly owned subsidiary of the Company (the “Business Combination”);

WHEREAS, after the closing of the Business Combination, the Holders will own shares of the Company’s Class A common stock, par value $0.0001 per share (the “Common Stock”), and Tortoise Borrower will own warrants to purchase 6,660,183 shares of Common Stock (the “Private Placement Warrants”); and

WHEREAS, the Company and the Holders desire to amend and restate the Existing Registration Rights Agreement, pursuant to which the Company shall grant the Holders certain registration rights with respect to certain securities of the Company, as set forth in this Agreement.

NOW, THEREFORE, in consideration of the representations, covenants and agreements contained herein, and certain other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the parties hereto, intending to be legally bound, hereby agree as follows:

ARTICLE 1
DEFINITIONS

1.1 Definitions. The terms defined in this Article 1 shall, for all purposes of this Agreement, have the respective meanings set forth below:

“Adverse Disclosure” shall mean any public disclosure of material non-public information, which disclosure, in the good faith judgment of the Chief Executive Officer or principal financial officer of the Company, after consultation with counsel to the Company, (i) would be required to be made in any Registration Statement or Prospectus in order for the applicable Registration Statement or Prospectus not to contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements contained therein (in the case of any prospectus and any preliminary prospectus, in the light of the circumstances under which they were made) not misleading, (ii) would not be required to be made at such time if the Registration Statement were not being filed and (iii) the Company has a bona fide business purpose for not making such information public.

“Agreement” shall have the meaning given in the Preamble.

“Atlas Point” shall have the meaning given in the Recitals hereto.

“Board” shall mean the board of directors of the Company.

“Business Combination” shall have the meaning given in the Recitals hereto.

“Commission” shall mean the Securities and Exchange Commission.

“Common Stock” shall have the meaning given in the Recitals hereto.

“Company” shall have the meaning given in the Preamble.

“Demanding Holder” shall mean, any Initial Holder or group of Initial Holders, that together elects to dispose of Registrable Securities having an aggregate value of at least $25 million, at the time of the Underwritten Demand, under a Registration Statement pursuant to an Underwritten Offering.

“Effectiveness Period” shall have the meaning given in subsection 3.1.1.

“Exchange Act” shall mean the Securities Exchange Act of 1934, as it may be amended from time to time.

“Existing Registration Rights Agreement” shall have the meaning given in the Recitals hereto.

“Form S-3” shall mean Form S-3 or any similar short-form registration statement that may be available at such time.

“Holder Indemnified Persons” shall have the meaning given in subsection 4.1.1.

“Holders” shall have the meaning given in the Preamble.

“Hyliion” shall have the meaning given in the Recitals hereto.

“Initial Holders” shall mean the Sponsor, Tortoise Borrower, Andrew J. Orekar, Frank M. Semple, Sidney L. Tassin, Vincent T. Cubbage, Stephen Pang, Steven C. Schnitzer, Darrell Brock, Evan Zimmer and Ed Russell.

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“Maximum Number of Securities” shall have the meaning given in subsection 2.1.4.

“Merger Sub” shall have the meaning given in the Recitals hereto.

“Misstatement” shall mean an untrue statement of a material fact or an omission to state a material fact required to be stated in a Registration Statement or Prospectus, or necessary to make the statements in a Registration Statement or Prospectus in the light of the circumstances under which they were made not misleading.

“Piggyback Registration” shall have the meaning given in subsection 2.2.1.

“Private Placement Warrants” shall have the meaning given in the Recitals hereto.

“Prospectus” shall mean the prospectus included in any Registration Statement, as supplemented by any and all prospectus supplements and as amended by any and all post-effective amendments and including all material incorporated by reference in such prospectus.

“Registrable Security” shall mean (a) the Private Placement Warrants (including any shares of Common Stock issued or issuable upon the exercise of any such Private Placement Warrants), (b) any outstanding share of Common Stock or any other equity security (including the shares of Common Stock issued or issuable upon the exercise of any other equity security) of the Company held by a Holder as of the date of this Agreement, which, for the avoidance of doubt, shall include shares of Common Stock received by a Holder on or after the date hereof as a distribution from the Sponsor in connection with its liquidation and dissolution, (c) any equity securities (including the shares of Common Stock issued or issuable upon the exercise of any such equity security) of the Company issuable upon conversion of any working capital loans in an amount up to $1,500,000 made to the Company by a Holder and (d) any other equity security of the Company issued or issuable with respect to any such share of Common Stock by way of a stock dividend or stock split or in connection with a combination of shares, recapitalization, merger, consolidation or reorganization; provided, however, that, as to any particular Registrable Securities, such securities shall cease to be Registrable Securities when: (A) a Registration Statement with respect to the sale of such securities shall have become effective under the Securities Act and such securities shall have been sold, transferred, disposed of or exchanged in accordance with such Registration Statement; (B) such securities shall have been otherwise transferred, new certificates for such securities not bearing a legend restricting further transfer shall have been delivered by the Company and subsequent public distribution of such securities shall not require registration under the Securities Act; (C) such securities shall have ceased to be outstanding; or (D) such securities may be sold without registration pursuant to Rule 144 promulgated under the Securities Act (or any successor rule promulgated thereafter by the Commission) (but with no volume or other restrictions or limitations).

“Registration” shall mean a registration effected by preparing and filing a registration statement or similar document in compliance with the requirements of the Securities Act, and the applicable rules and regulations promulgated thereunder, and any such registration statement having become effective by the Commission.

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“Registration Expenses” shall mean the out-of-pocket expenses of a Registration, including, without limitation, the following:

(a) all registration and filing fees (including fees with respect to filings required to be made with the Financial Industry Regulatory Authority) and any securities exchange on which the Common Stock is then listed;

(b) fees and expenses of compliance with securities or blue sky laws (including reasonable fees and disbursements of counsel for the Underwriters in connection with blue sky qualifications of Registrable Securities);

(c) printing, messenger, telephone and delivery expenses;

(d) reasonable fees and disbursements of counsel for the Company;

(e) reasonable fees and disbursements of all independent registered public accountants of the Company incurred specifically in connection with such Registration; and

(f) reasonable fees and expenses of one (1) legal counsel selected by the Demanding Holders initiating a Underwritten Demand to be registered for offer and sale in the applicable Registration or Underwritten Offering.

“Registration Statement” shall mean any registration statement under the Securities Act that covers the Registrable Securities pursuant to the provisions of this Agreement, including the Prospectus included in such registration statement, amendments (including post-effective amendments) and supplements to such registration statement and all exhibits to and all material incorporated by reference in such registration statement.

“Requesting Holder” shall have the meaning given in subsection 2.1.3.

“Securities Act” shall mean the Securities Act of 1933, as amended from time to time.

“Shelf Registration” shall have the meaning given in subsection 2.1.1.

“Sponsor” shall have the meaning given in the Preamble.

“Tortoise Borrower” shall have the meaning given in the Preamble.

“Underwriter” shall mean a securities dealer who purchases any Registrable Securities as principal in an Underwritten Offering and not as part of such dealer’s market-making activities.

“Underwritten Demand” shall have the meaning given in subsection 2.1.3.

“Underwritten Offering” shall mean a Registration in which securities of the Company are sold to an Underwriter in a firm commitment underwriting for distribution to the public.

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ARTICLE 2
REGISTRATIONS

2.1 Registration.

2.1.1 Shelf Registration. The Company agrees that, within thirty (30) calendar days after the consummation of the Business Combination, the Company will file with the Commission (at the Company’s sole cost and expense) a Registration Statement registering the resale of the Registrable Securities (a “Shelf Registration”). The Company shall use its reasonable best efforts to cause such Registration Statement to become effective by the Commission as soon as reasonably practicable after the initial filing of the Registration Statement in accordance with Section 3.1 of this Agreement.

2.1.2 Effective Registration. Notwithstanding the provisions of subsection 2.1.1 above or any other part of this Agreement, a Registration pursuant to a Shelf Registration shall not count as a Registration unless and until (i) the Registration Statement filed with the Commission with respect to a Registration pursuant to a Shelf Registration has become effective by the Commission and (ii) the Company has complied with all of its obligations under this Agreement with respect thereto. Subject to the limitations contained in this Agreement, the Company shall effect any Shelf Registration on such appropriate registration form of the Commission (x) as shall be selected by the Company and (y) as shall permit the resale of the Registrable Securities by the Holders. If at any time a Registration Statement on Form S-3 filed with the Commission pursuant to Section 2.1.1 is effective and a Holder provides written notice to the Company that it intends to effect an offering of all or part of the Registrable Securities included on such Registration Statement, the Company will amend or supplement such Registration Statement as may be necessary in order to enable such offering to take place in accordance with the terms of this Agreement.

2.1.3 Underwritten Offering. Subject to the provisions of subsection 2.1.4 and Section 2.3 hereof, any Demanding Holder may make a written demand for an Underwritten Offering pursuant to a Registration Statement filed with the Commission in accordance with Section 2.1.1 (an “Underwritten Demand”). The Company shall, within ten (10) days of the Company’s receipt of the Underwritten Demand, notify, in writing, all other Holders of such demand, and each Holder who thereafter wishes to include all or a portion of such Holder’s Registrable Securities in such Underwritten Offering pursuant to an Underwritten Demand (each such Holder that includes all or a portion of such Holder’s Registrable Securities in such Underwritten Offering, a “Requesting Holder”) shall so notify the Company, in writing, within two (2) days (one (1) day if such offering is an overnight or bought Underwritten Offering) after the receipt by the Holder of the notice from the Company. Upon receipt by the Company of any such written notification from a Requesting Holder(s), such Requesting Holder(s) shall be entitled to have their Registrable Securities included in the Underwritten Offering pursuant to an Underwritten Demand. All such Holders proposing to distribute their Registrable Securities through an Underwritten Offering under this subsection 2.1.3 shall enter into an underwriting agreement in customary form with the Underwriter(s) selected for such Underwritten Offering by the Demanding Holders initiating the Underwritten Offering. Notwithstanding the foregoing, the Company is not obligated to effect more than an aggregate of three (3) Underwritten Offerings pursuant to this subsection 2.1.3 and is not obligated to effect an Underwritten Offering pursuant to this subsection 2.1.3 within ninety (90) days after the closing of an Underwritten Offering.

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2.1.4 Reduction of Underwritten Offering. If the managing Underwriter or Underwriters in an Underwritten Offering pursuant to a Underwritten Demand, in good faith, advises the Company, the Demanding Holders, the Requesting Holders and other persons or entities holding Common Stock or other equity securities of the Company that the Company is obligated to include pursuant to separate written contractual arrangements with such persons or entities (if any) in writing that the dollar amount or number of Registrable Securities or other equity securities of the Company requested to be included in such Underwritten Offering exceeds the maximum dollar amount or maximum number of equity securities of the Company that can be sold in the Underwritten Offering without adversely affecting the proposed offering price, the timing, the distribution method or the probability of success of such offering (such maximum dollar amount or maximum number of such securities, as applicable, the “Maximum Number of Securities”), then the Company shall include in such Underwritten Offering, as follows: (i) first, the Registrable Securities of the Demanding Holders and the Requesting Holders (if any) (pro rata based on the respective number of Registrable Securities that each Demanding Holder and Requesting Holder (if any) has requested be included in such Underwritten Offering and the aggregate number of Registrable Securities that the Demanding Holders and Requesting Holders have requested be included in such Underwritten Offering (such proportion is referred to herein as “Pro Rata”)) that can be sold without exceeding the Maximum Number of Securities; (ii) second, to the extent that the Maximum Number of Securities has not been reached under the foregoing clause (i), Common Stock or other equity securities of the Company that the Company desires to sell and that can be sold without exceeding the Maximum Number of Securities; and (iii) third, to the extent that the Maximum Number of Securities has not been reached under the foregoing clauses (i) and (ii), Common Stock or other equity securities of the Company held by other persons or entities that the Company is obligated to include pursuant to separate written contractual arrangements with such persons or entities and that can be sold without exceeding the Maximum Number of Securities.

2.2 Piggyback Registration.

2.2.1 Piggyback Rights. If the Company proposes to (i) file a Registration Statement under the Securities Act with respect to an offering of equity securities of the Company, or securities or other obligations exercisable or exchangeable for, or convertible into equity securities of the Company, for its own account or for the account of stockholders of the Company, other than a Registration Statement (A) filed in connection with any employee stock option or other benefit plan, (B) for an exchange offer or offering of securities solely to the Company’s existing stockholders, (C) for an offering of debt that is convertible into equity securities of the Company or (D) for a dividend reinvestment plan, or (ii) consummate an Underwritten Offering for its own account or for the account of stockholders of the Company, then the Company shall give written notice of such proposed action to all of the Holders as soon as practicable (but in the case of filing a Registration Statement, not less than ten (10) days before the anticipated filing date of such Registration Statement), which notice shall (x) describe the amount and type of securities to be included, the intended method(s) of distribution and the name of the proposed managing Underwriter or Underwriters, if any, and (y) offer to all of the Holders the opportunity to register the sale of such number of Registrable Securities as such Holders may request in writing within (a) five (5) days in the case of filing a Registration Statement and (b) two (2) days in the case of an Underwritten Offering (unless such offering is an overnight or bought Underwritten Offering, then one (1) day), in each case after receipt of such written notice (such Registration a “Piggyback Registration”). The Company shall, in good faith, cause such Registrable Securities to be included in such Piggyback Registration and shall use its best efforts to cause the managing Underwriter or Underwriters of a proposed Underwritten Offering to permit the Registrable Securities requested by the Holders pursuant to this subsection 2.2.1 to be included in a Piggyback Registration on the same terms and conditions as any similar securities of the Company included in such Piggyback Registration and to permit the sale or other disposition of such Registrable Securities in accordance with the intended method(s) of distribution thereof. All such Holders proposing to include Registrable Securities in an Underwritten Offering under this subsection 2.2.1 shall enter into an underwriting agreement in customary form with the Underwriter(s) selected for such Underwritten Offering by the Company.

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2.2.2 Reduction of Piggyback Registration. If the managing Underwriter or Underwriters in an Underwritten Offering that is to be a Piggyback Registration, in good faith, advises the Company and the Holders of Registrable Securities participating in the Piggyback Registration in writing that the dollar amount or number of shares of the equity securities of the Company that the Company desires to sell, taken together with (i) the shares of equity securities of the Company, if any, as to which Registration or Underwritten Offering has been demanded pursuant to separate written contractual arrangements with persons or entities other than the Holders of Registrable Securities hereunder, (ii) the Registrable Securities as to which Registration or Underwritten Offering has been requested pursuant to Section 2.2 hereof and (iii) the shares of equity securities of the Company, if any, as to which Registration or Underwritten Offering has been requested pursuant to separate written contractual piggyback registration rights of other stockholders of the Company, exceeds the Maximum Number of Securities, then:

(a) If the Registration or Underwritten Offering is undertaken for the Company’s account, the Company shall include in any such Registration or Underwritten Offering (A) first, the Common Stock or other equity securities of the Company that the Company desires to sell, which can be sold without exceeding the Maximum Number of Securities; (B) second, to the extent that the Maximum Number of Securities has not been reached under the foregoing clause (A), the Registrable Securities of Holders exercising their rights to register their Registrable Securities pursuant to subsection 2.2.1 hereof, Pro Rata, which can be sold without exceeding the Maximum Number of Securities; and (C) third, to the extent that the Maximum Number of Securities has not been reached under the foregoing clauses (A) and (B), Common Stock or other equity securities of the Company, if any, as to which Registration or Underwritten Offering has been requested pursuant to written contractual piggyback registration rights of other stockholders of the Company, which can be sold without exceeding the Maximum Number of Securities; or

(b) If the Registration or Underwritten Offering is pursuant to a request by persons or entities other than the Holders of Registrable Securities, then the Company shall include in any such Registration or Underwritten Offering (A) first, Common Stock or other equity securities of the Company, if any, of such requesting persons or entities, other than the Holders of Registrable Securities, which can be sold without exceeding the Maximum Number of Securities; (B) second, to the extent that the Maximum Number of Securities has not been reached under the foregoing clause (A), the Registrable Securities of Holders exercising their rights to register their Registrable Securities pursuant to subsection 2.2.1, Pro Rata, which can be sold without exceeding the Maximum Number of Securities; (C) third, to the extent that the Maximum Number of Securities has not been reached under the foregoing clauses (A) and (B), Common Stock or other equity securities of the Company that the Company desires to sell, which can be sold without exceeding the Maximum Number of Securities; and (D) fourth, to the extent that the Maximum Number of Securities has not been reached under the foregoing clauses (A), (B) and (C), Common Stock or other equity securities of the Company for the account of other persons or entities that the Company is obligated to register pursuant to separate written contractual arrangements with such persons or entities, which can be sold without exceeding the Maximum Number of Securities.

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2.2.3 Piggyback Registration Withdrawal. Any Holder of Registrable Securities shall have the right to withdraw from a Piggyback Registration for any or no reason whatsoever upon written notification to the Company and the Underwriter or Underwriters (if any) of his, her or its intention to withdraw from such Piggyback Registration prior to the effectiveness of the Registration Statement filed with the Commission with respect to such Piggyback Registration. The Company (whether on its own good faith determination or as the result of a request for withdrawal by persons pursuant to separate written contractual obligations) may withdraw a Registration Statement filed with the Commission in connection with a Piggyback Registration at any time prior to the effectiveness of such Registration Statement. Notwithstanding anything to the contrary in this Agreement, the Company shall be responsible for the Registration Expenses incurred in connection with the Piggyback Registration prior to its withdrawal under this subsection 2.2.3.

2.2.4 Unlimited Piggyback Registration Rights. For purposes of clarity, any Registration or Underwritten Offering effected pursuant to Section 2.2 hereof shall not be counted as an Underwritten Offering pursuant to an Underwritten Demand effected under Section 2.1 hereof.

2.3 Restrictions on Registration Rights. If (A) the Holders have requested an Underwritten Offering pursuant to an Underwritten Demand and the Company and the Holders are unable to obtain the commitment of underwriters to firmly underwrite the offer; or (B) the Holders have requested an Underwritten Offering pursuant to an Underwritten Demand and in the good faith judgment of the Board such Registration or Underwritten Offering would be seriously detrimental to the Company and the Board concludes as a result that it is essential to defer the filing of such Registration Statement or the undertaking of such Underwritten Offering at such time, then in each case the Company shall furnish to such Holders a certificate signed by the Chairman of the Board stating that in the good faith judgment of the Board it would be seriously detrimental to the Company for such Registration Statement to be filed or to undertake such Underwritten Offering in the near future and that it is therefore essential to defer the filing of such Registration Statement or undertaking of such Underwritten Offering. In such event, the Company shall have the right to defer such filing or offering for a period of not more than thirty (30) days; provided, however, that the Company shall not defer its obligation in this manner more than once in any twelve (12)-month period.

ARTICLE 3
COMPANY PROCEDURES

3.1 General Procedures. The Company shall use its reasonable best efforts to effect such Registration to permit the sale of such Registrable Securities in accordance with the intended plan of distribution thereof, and pursuant thereto the Company shall, as expeditiously as possible and to the extent applicable:

3.1.1 prepare and file with the Commission within thirty (30) days after the consummation of the Business Combination a Registration Statement with respect to such Registrable Securities and use its reasonable best efforts to cause such Registration Statement to become effective and remain effective, including filing a replacement Registration Statement, if necessary, until all Registrable Securities covered by such Registration Statement have been sold or are no longer outstanding (such period, the “Effectiveness Period”);

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3.1.2 prepare and file with the Commission such amendments and post-effective amendments to the Registration Statement, and such supplements to the Prospectus, as may be reasonably requested by the Demanding Holders or any Underwriter or as may be required by the rules, regulations or instructions applicable to the registration form used by the Company or by the Securities Act or rules and regulations thereunder to keep the Registration Statement effective until all Registrable Securities covered by such Registration Statement are sold in accordance with the intended plan of distribution set forth in such Registration Statement or supplement to the Prospectus or are no longer outstanding;

3.1.3 prior to filing a Registration Statement or Prospectus, or any amendment or supplement thereto, furnish without charge to the Underwriters, if any, and the Holders of Registrable Securities included in such Registration or Underwritten Offering, and such Holders’ legal counsel, copies of such Registration Statement as proposed to be filed, each amendment and supplement to such Registration Statement (in each case including all exhibits thereto and documents incorporated by reference therein), the Prospectus (including each preliminary Prospectus) and such other documents as the Underwriters and the Holders of Registrable Securities included in such Registration or the legal counsel for any such Holders may reasonably request in order to facilitate the disposition of the Registrable Securities owned by such Holders; provided, that the Company will not have any obligation to provide any document pursuant to this clause that is available on the Commission’s EDGAR system;

3.1.4 prior to any Underwritten Offering of Registrable Securities, use its best efforts to (i) register or qualify the Registrable Securities covered by the Registration Statement under such securities or “blue sky” laws of such jurisdictions in the United States as the Holders of Registrable Securities included in such Registration Statement (in light of their intended plan of distribution) may request and (ii) take such action necessary to cause such Registrable Securities covered by the Registration Statement to be registered with or approved by such other governmental authorities as may be necessary by virtue of the business and operations of the Company and do any and all other acts and things that may be necessary or advisable to enable the Holders of Registrable Securities included in such Registration Statement to consummate the disposition of such Registrable Securities in such jurisdictions; provided, however, that the Company shall not be required to qualify generally to do business in any jurisdiction where it would not otherwise be required to qualify or take any action to which it would be subject to general service of process or taxation in any such jurisdiction where it is not then otherwise so subject;

3.1.5 cause all such Registrable Securities to be listed on each securities exchange or automated quotation system on which similar securities issued by the Company are then listed;

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3.1.6 provide a transfer agent or warrant agent, as applicable, and registrar for all such Registrable Securities no later than the effective date of such Registration Statement;

3.1.7 advise each seller of such Registrable Securities, promptly after it shall receive notice or obtain knowledge thereof, of the issuance of any stop order by the Commission suspending the effectiveness of such Registration Statement or the initiation or threatening of any proceeding for such purpose and promptly use its reasonable best efforts to prevent the issuance of any stop order or to obtain its withdrawal if such stop order should be issued;

3.1.8 during the Effectiveness Period, furnish a conformed copy of each filing of any Registration Statement or Prospectus or any amendment or supplement to such Registration Statement or Prospectus or any document that is to be incorporated by reference into such Registration Statement or Prospectus, promptly after such filing of such documents with the Commission to each seller of such Registrable Securities or its counsel; provided, that the Company will not have any obligation to provide any document pursuant to this clause that is available on the Commission’s EDGAR system;

3.1.9 notify the Holders at any time when a Prospectus relating to such Registration Statement is required to be delivered under the Securities Act, of the happening of any event as a result of which the Prospectus included in such Registration Statement, as then in effect, includes a Misstatement, and then to correct such Misstatement as set forth in Section 3.4 hereof;

3.1.10 permit a representative of the Holders, the Underwriters, if any, and any attorney or accountant retained by such Holders or Underwriter to participate, at each such person’s own expense, in the preparation of the Registration Statement or the Prospectus, and cause the Company’s officers, directors and employees to supply all information reasonably requested by any such representative, Underwriter, attorney or accountant in connection with the Registration; provided, however, that such representatives or Underwriters enter into a confidentiality agreement, in form and substance reasonably satisfactory to the Company, prior to the release or disclosure of any such information;

3.1.11 obtain a comfort letter from the Company’s independent registered public accountants in the event of an Underwritten Offering, in customary form and covering such matters of the type customarily covered by comfort letters as the managing Underwriter may reasonably request, and reasonably satisfactory to a majority-in-interest of the participating Holders;

3.1.12 on the date the Registrable Securities are delivered for sale pursuant to such Registration, obtain an opinion, dated such date, of counsel representing the Company for the purposes of such Registration, addressed to the placement agent or sales agent, if any, and the Underwriters, if any, covering such legal matters with respect to the Registration in respect of which such opinion is being given as the placement agent, sales agent, or Underwriter may reasonably request and as are customarily included in such opinions and negative assurance letters, and reasonably satisfactory to such placement agent, sales agent or Underwriter;

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3.1.13 in the event of any Underwritten Offering, enter into and perform its obligations under an underwriting agreement, in usual and customary form, with the managing Underwriter of such offering;

3.1.14 make available to its security holders, as soon as reasonably practicable, an earnings statement covering the period of at least twelve (12) months beginning with the first day of the Company’s first full calendar quarter after the effective date of the Registration Statement which satisfies the provisions of Section 11(a) of the Securities Act and Rule 158 thereunder (or any successor rule promulgated thereafter by the Commission);

3.1.15 use its reasonable efforts to make available senior executives of the Company to participate in customary “road show” presentations that may be reasonably requested by the Underwriter in any Underwritten Offering; and

3.1.16 otherwise, in good faith, cooperate reasonably with, and take such customary actions as may reasonably be requested by the Holders, in connection with such Registration.

3.2 Registration Expenses. The Registration Expenses in respect of all Registrations shall be borne by the Company. It is acknowledged by the Holders that the Holders shall bear all incremental selling expenses relating to the sale of Registrable Securities, such as Underwriters’ commissions and discounts, brokerage fees, Underwriter marketing costs and, other than as set forth in the definition of “Registration Expenses,” all reasonable fees and expenses of any legal counsel representing the Holders.

3.3 Requirements for Participation in Underwritten Offerings. No person or entity may participate in any Underwritten Offering for equity securities of the Company pursuant to a Registration initiated by the Company hereunder unless such person or entity (i) agrees to sell such person’s or entity’s securities on the basis provided in any underwriting arrangements approved by the Company and (ii) completes and executes all customary questionnaires, powers of attorney, indemnities, lock-up agreements, underwriting agreements and other customary documents as may be reasonably required under the terms of such underwriting arrangements.

3.4 Suspension of Sales; Adverse Disclosure. Upon receipt of written notice from the Company that a Registration Statement or Prospectus contains a Misstatement, each of the Holders shall forthwith discontinue disposition of Registrable Securities until he, she or it has received copies of a supplemented or amended Prospectus correcting the Misstatement (it being understood that the Company hereby covenants to prepare and file such supplement or amendment as soon as practicable after the time of such notice), or until he, she or it is advised in writing by the Company that the use of the Prospectus may be resumed. If the filing, initial effectiveness or continued use of a Registration Statement in respect of any Registration or Underwritten Offering at any time would require the Company to make an Adverse Disclosure or would require the inclusion in such Registration Statement of financial statements that are unavailable to the Company for reasons beyond the Company’s control, the Company may, upon giving prompt written notice of such action to the Holders, delay the filing or initial effectiveness of, or suspend use of, such Registration Statement for the shortest period of time, but in no event more than thirty (30) days, determined in good faith by the Company to be necessary for such purpose. In the event the Company exercises its rights under the preceding sentences in this Section 3.4, the Holders agree to suspend, immediately upon their receipt of the notices referred to in this Section 3.4, their use of the Prospectus relating to any Registration in connection with any sale or offer to sell Registrable Securities. The Company shall immediately notify the Holders of the expiration of any period during which it exercised its rights under this Section 3.4.

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3.5 Reporting Obligations. As long as any Holder shall own Registrable Securities, the Company, at all times while it shall be a reporting company under the Exchange Act, covenants to file timely (or obtain extensions in respect thereof and file within the applicable grace period) all reports required to be filed by the Company after the date hereof pursuant to Section 13(a) or 15(d) of the Exchange Act. The Company further covenants that it shall take such further action as any Holder may reasonably request, all to the extent required from time to time to enable such Holder to sell shares of Registrable Securities held by such Holder without registration under the Securities Act within the limitation of the exemptions provided by Rule 144 promulgated under the Securities Act (or any successor rule promulgated thereafter by the Commission), including providing any legal opinions. Upon the request of any Holder, the Company shall deliver to such Holder a written certification of a duly authorized officer as to whether it has complied with such requirements.

ARTICLE 4
INDEMNIFICATION AND CONTRIBUTION

4.1 Indemnification.

4.1.1 The Company agrees to indemnify, to the extent permitted by law, each Holder of Registrable Securities, its officers and directors and each person who controls such Holder (within the meaning of the Securities Act) (collectively, the “Holder Indemnified Persons”) against all losses, claims, damages, liabilities and expenses (including reasonable attorneys’ fees and inclusive of all reasonable attorneys’ fees arising out of the enforcement of each such persons’ rights under this Section 4.1) resulting from any untrue or alleged untrue statement of material fact contained in any Registration Statement, Prospectus or preliminary Prospectus or any amendment thereof or supplement thereto or any omission or alleged omission of a material fact required to be stated therein or necessary to make the statements therein, in the light of the circumstances in which they were made, not misleading, except insofar as the same are caused by or contained in any information furnished in writing to the Company by or on behalf of such Holder Indemnified Person specifically for use therein.

4.1.2 In connection with any Registration Statement in which a Holder of Registrable Securities is participating, such Holder shall furnish to the Company in writing such information and affidavits as the Company reasonably requests for use in connection with any such Registration Statement or Prospectus and, to the extent permitted by law, shall, severally and not jointly, indemnify the Company, its directors and officers and agents and each person who controls the Company (within the meaning of the Securities Act) against any losses, claims, damages, liabilities and expenses (including reasonable attorneys’ fees and inclusive of all reasonable attorneys’ fees arising out of the enforcement of each such persons’ rights under this Section 4.1) resulting from any untrue or alleged untrue statement of material fact contained in any Registration Statement, Prospectus or preliminary Prospectus or any amendment thereof or supplement thereto or any omission or alleged omission of a material fact required to be stated therein or necessary to make the statements therein, in the light of the circumstances in which they were made, not misleading, but only to the extent that the same are made in reliance on and in conformity with information relating to the Holder so furnished in writing to the Company by or on behalf of such Holder specifically for use therein. In no event shall the liability of any selling Holder hereunder be greater in amount than the net proceeds received by such Holder from the sale of Registrable Securities pursuant to such Registration Statement giving rise to such indemnification obligation.

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4.1.3 Any person entitled to indemnification herein shall (i) give prompt written notice to the indemnifying party of any claim with respect to which it seeks indemnification (provided that the failure to give prompt notice shall not impair any person’s right to indemnification hereunder to the extent such failure has not materially prejudiced the indemnifying party) and (ii) unless in such indemnified party’s reasonable judgment a conflict of interest between such indemnified and indemnifying parties may exist with respect to such claim or there may be reasonable defenses available to the indemnified party that are different from or additional to those available to the indemnifying party, permit such indemnifying party to assume the defense of such claim with counsel reasonably satisfactory to the indemnified party. If such defense is assumed, the indemnifying party shall not be subject to any liability for any settlement made by the indemnified party without its consent (but such consent shall not be unreasonably withheld). An indemnifying party who is not entitled to, or elects not to, assume the defense of a claim shall not be obligated to pay the fees and expenses of more than one counsel for all parties indemnified by such indemnifying party with respect to such claim, unless in the reasonable judgment of any indemnified party a conflict of interest may exist between such indemnified party and any other of such indemnified parties with respect to such claim. No indemnifying party shall, without the consent of the indemnified party, consent to the entry of any judgment or enter into any settlement which cannot be settled in all respects by the payment of money (and such money is so paid by the indemnifying party pursuant to the terms of such settlement) or which settlement does not include as an unconditional term thereof the giving by the claimant or plaintiff to such indemnified party of a release from all liability in respect to such claim or litigation.

4.1.4 The indemnification provided for under this Agreement shall remain in full force and effect regardless of any investigation made by or on behalf of the indemnified party or any officer, director or controlling person of such indemnified party and shall survive the transfer of securities.

4.1.5 If the indemnification provided under Section 4.1 is held by a court of competent jurisdiction to be unavailable to an indemnified party in respect of any losses, claims, damages, liabilities and expenses referred to herein, then the indemnifying party, in lieu of indemnifying the indemnified party, shall to the extent permitted by law contribute to the amount paid or payable by the indemnified party as a result of such losses, claims, damages, liabilities and expenses in such proportion as is appropriate to reflect the relative fault of the indemnifying party and the indemnified party, as well as any other relevant equitable considerations. The relative fault of the indemnifying party and indemnified party shall be determined by a court of law by reference to, among other things, whether the untrue or alleged untrue statement of a material fact or the omission or alleged omission to state a material fact relates to information supplied by such indemnifying party or such indemnified party and the indemnifying party’s and indemnified party’s relative intent, knowledge, access to information and opportunity to correct or prevent such action; provided, however, that the liability of any Holder under this subsection 4.1.5 shall be limited to the amount of the net proceeds received by such Holder in such offering giving rise to such liability. The amount paid or payable by a party as a result of the losses or other liabilities referred to above shall be deemed to include, subject to the limitations set forth in subsections 4.1.1, 4.1.2 and 4.1.3 above, any legal or other fees, charges or expenses reasonably incurred by such party in connection with any investigation or proceeding. The parties hereto agree that it would not be just and equitable if contribution pursuant to this subsection 4.1.5 were determined by pro rata allocation or by any other method of allocation, which does not take account of the equitable considerations referred to in this subsection 4.1.5. No person guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the Securities Act) shall be entitled to contribution pursuant to this subsection 4.1.5 from any person who was not guilty of such fraudulent misrepresentation.

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ARTICLE 5
MISCELLANEOUS

5.1 Notices. Any notice or communication under this Agreement must be in writing and given by (i) deposit in the United States mail, addressed to the party to be notified, postage prepaid and registered or certified with return receipt requested, (ii) delivery in person or by courier service providing evidence of delivery or (iii) transmission by hand delivery, telecopy, telegram, facsimile or email. Each notice or communication that is mailed, delivered or transmitted in the manner described above shall be deemed sufficiently given, served, sent, and received, in the case of mailed notices, on the third (3rd) business day following the date on which it is mailed, in the case of notices delivered by courier service, hand delivery, telecopy or telegram, at such time as it is delivered to the addressee (with the delivery receipt or the affidavit of messenger) or at such time as delivery is refused by the addressee upon presentation, and in the case of notices delivered by facsimile or email, at such time as it is successfully transmitted to the addressee. Any notice or communication under this Agreement must be addressed, if to the Company, to: 1202 BMC Drive, Cedar Park, TX 78613, or by email at: thomas@hyliion.com if to the Sponsor or Tortoise Borrower, to: 5100 W. 115^th Place, Leawood, KS 66211, or by email at: JKruske@tortoiseadvisors.com, and, if to any other Holder, to the address of such Holder as it appears in the applicable register for the Registrable Securities or such other address as may be designated in writing by such Holder (including on the signature pages hereto). Any party may change its address for notice at any time and from time to time by written notice to the other parties hereto, and such change of address shall become effective thirty (30) days after delivery of such notice as provided in this Section 5.1.

5.2 Assignment; No Third Party Beneficiaries.

5.2.1 This Agreement and the rights, duties and obligations of the Company hereunder may not be assigned or delegated by the Company in whole or in part.

5.2.2 This Agreement and the provisions hereof shall be binding upon and shall inure to the benefit of each of the parties and its successors.

5.2.3 This Agreement shall not confer any rights or benefits on any persons that are not parties hereto, other than as expressly set forth in this Agreement and Section 5.2 hereof.

5.2.4 No assignment by any party hereto of such party’s rights, duties and obligations hereunder shall be binding upon or obligate the Company unless and until the Company shall have received (i) written notice of such assignment as provided in Section 5.1 hereof and (ii) the written agreement of the assignee, in a form reasonably satisfactory to the Company, to be bound by the terms and provisions of this Agreement (which may be accomplished by an addendum or certificate of joinder to this Agreement). Any transfer or assignment made other than as provided in this Section 5.2 shall be null and void.

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5.3 Counterparts. This Agreement may be executed in multiple counterparts (including facsimile or PDF counterparts), each of which shall be deemed an original, and all of which together shall constitute the same instrument, but only one of which need be produced.

5.4 Governing Law; Venue. NOTWITHSTANDING THE PLACE WHERE THIS AGREEMENT MAY BE EXECUTED BY ANY OF THE PARTIES HERETO, THE PARTIES EXPRESSLY AGREE THAT THIS AGREEMENT SHALL BE GOVERNED BY AND CONSTRUED UNDER THE LAWS OF THE STATE OF NEW YORK AS APPLIED TO AGREEMENTS AMONG NEW YORK RESIDENTS ENTERED INTO AND TO BE PERFORMED ENTIRELY WITHIN NEW YORK, WITHOUT REGARD TO THE CONFLICT OF LAW PROVISIONS OF SUCH JURISDICTION.

5.5 Amendments and Modifications. Upon the written consent of the Company and the Holders of at least a majority in interest of the Registrable Securities at the time in question, compliance with any of the provisions, covenants and conditions set forth in this Agreement may be waived, or any of such provisions, covenants or conditions may be amended or modified; provided, however, that notwithstanding the foregoing, any amendment hereto or waiver hereof that adversely affects one Holder, solely in his, her or its capacity as a holder of the shares of capital stock of the Company, in a manner that is materially different from the other Holders (in such capacity) shall require the consent of the Holder so affected. No course of dealing between any Holder or the Company and any other party hereto or any failure or delay on the part of a Holder or the Company in exercising any rights or remedies under this Agreement shall operate as a waiver of any rights or remedies of any Holder or the Company. No single or partial exercise of any rights or remedies under this Agreement by a party shall operate as a waiver or preclude the exercise of any other rights or remedies hereunder or thereunder by such party.

5.6 Other Registration Rights. The Company represents and warrants that no person, other than (a) a Holder of Registrable Securities, (b) the parties to those certain Subscription Agreements, dated as of June 18, 2020, by and between the Company and certain investors, and (c) Atlas Point Energy Infrastructure Fund, LLC, pursuant to that certain Amended and Restated Forward Purchase Agreement, dated as of February 6, 2019, as amended, by and among the Company, the Sponsor and Atlas Point Energy Infrastructure Fund, LLC, has any right to require the Company to register any securities of the Company for sale or to include such securities of the Company in any Registration filed by the Company for the sale of securities for its own account or for the account of any other person. Further, the Company represents and warrants that this Agreement supersedes any other registration rights agreement or agreement with similar terms and conditions and in the event of a conflict between any such agreement or agreements and this Agreement, the terms of this Agreement shall prevail.

5.7 Term. This Agreement shall terminate upon the earlier of (i) the tenth (10th) anniversary of the date of this Agreement and (ii) the date as of which the Holders cease to hold any Registrable Securities. The provisions of Article 4 shall survive any termination.

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IN WITNESS WHEREOF, the undersigned have caused this Agreement to be executed as of the date first written above.

COMPANY:
HYLIION HOLDINGS CORP.,
a Delaware corporation
By:	/s/ Thomas Healy
Name:	Thomas Healy
Title:	Chief Executive Officer

AXIOMA VENTURES, LLC
By: Axioma Holdings, LLC Its Sole Member By: Axioma Management, LLC Its Manager	By: Axioma Holdings, LLC Its: Sole Member By: Axioma Management, LLC Its: Manager
By: /s/ Howard Jenkins Name: Howard Jenkins Title: Manager	By: /s/ Howard Jenkins Name: Howard Jenkins Title: Manager Address for notice: * Attention: Howard Jenkins Electronic Mail: *